Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, can be detected in respiratory samples by Real-time Reverse Transcriptase (RT)-PCR or other molecular methods. Accessibility of diagnostic testing for COVID-19 has been limited by intermittent shortages of supplies required for testing, including flocked nasopharyngeal (FLNP) swabs. Methods We developed a 3D-printed nasopharyngeal (3DP) swab as a replacement of the FLNP swab. The performance of 3DP and FLNP swabs were compared in a clinical trial of symptomatic patients at three clinical sites (n=291) using three SARS-CoV-2 EUA tests: a modified version of the CDC Real-time Reverse Transcriptase (RT)-PCR Diagnostic Panel and two commercial automated formats, Roche Cobas and NeuMoDx. Results The cycle threshold (C(t)) values from the gene targets and the RNase P gene control in the CDC assay showed no significant differences between swabs for both gene targets (p=0.152 and p=0.092), with the RNase P target performing significantly better in the 3DP swabs (p & 0.001). The C(t) values showed no significant differences between swabs for both viral gene targets in the Roche cobas assay (p=0.05 and p=0.05) as well as the NeuMoDx assay (p=0.401 and p=0.484). The overall clinical correlation of COVID-19 diagnosis between all methods was 95.88% (Kappa 0.901). Conclusions 3DP swabs were equivalent to standard FLNP in three testing platforms for SARS-CoV-2. Given the need for widespread testing, 3DP swabs printed on-site are an alternate to FLNP that can rapidly scale in response to acute needs when supply chain disruptions affect availability of collection kits.

Background Nasal osteotomy is a commonly performed procedure during rhinoplasty for both functional and cosmetic reasons. Teaching and learning this procedure proves difficult due to the reliance on nuanced tactile feedback. For surgical simulation, trainees are traditionally limited to cadaveric bones, which can be costly and difficult to obtain. Objective This study aimed to design and print a low-cost midface model for nasal osteotomy simulation. Methods A 3D reconstruction of the midface was modified using the free open-source design software Meshmixer (Autodesk Inc). The pyriform aperture was smoothed, and support rods were added to hold the fragments generated from the simulation in place. Several models with various infill densities were printed using a desktop 3D printer to determine which model best mimicked human facial bone. Results A midface simulation set was designed using a desktop 3D printer, polylactic acid filament, and easily accessible tools. A nasal osteotomy procedure was successfully simulated using the model. Conclusions 3D printing is a low-cost, accessible technology that can be used to create simulation models. With growing restrictions on trainee duty hours, the simulation set can be used by programs to augment surgical training.

Our aim in this prospective radiological study was to determine whether the flexibility rate calculated from radiographs obtained during forced traction under general anaesthesia, was better than that of fulcrum-bending radiographs before corrective surgery in predicting the extent of the available correction in patients with idiopathic scoliosis. We evaluated 33 patients with a Cobb angle > 60 degrees on a standing posteroanterior radiograph, who had been treated by posterior correction. Pre-operative standing fulcrum-bending radiographs and those with forced-traction under general anaesthesia were obtained. Post-operative standing radiographs were taken after surgical correction. The mean forced-traction flexibility rate was 55% (SD 11.3) which was significantly higher than the mean fulcrum-bending flexibility rate of 32% (SD 16.1) (p < 0.001). We found no correlation between either the forced-traction or fulcrum-bending flexibility rates and the correction rate post-operatively (p = 0.24 and p = 0.44, respectively). Radiographs obtained during forced traction under general anaesthesia were better at predicting the flexibility of the curve than fulcrum-bending radiographs in curves with a Cobb angle > 60 degrees in the standing position and may identify those patients for whom supplementary anterior surgery can be avoided.

Study Design:Retrospective radiographic review.Objectives:Our objectives were to (1) compare the ability of fulcrum bend radiographs and traction radiographs under general anesthesia to predict correction of adolescent idiopathic scoliosis (AIS) using pedicle screw only constructs and (2) compare the fulcrum bend correction index (FBCI) with a new measurement: the traction correction index (TCI).Methods:This is a retrospective radiographic review of 80 AIS patients (62 female and 18 male), who underwent scoliosis correction with pedicle screw only constructs. The mean age at surgery was 14 years (range 9-20 years). Radiographic analysis was carried out on the preoperative and immediate postoperative posteroanterior standing radiographs and the preoperative fulcrum bend radiographs and traction radiographs under general anesthesia. FBCI is calculated by dividing the correction rate by the fulcrum flexibility and TCI is calculated by dividing the correction rate by the traction flexibility.Results:Preoperative mean Cobb angle of 63.9° was corrected to 25.8° postoperatively. The mean fulcrum bending Cobb angle was 37.6° and traction Cobb angle was 26.6°. The mean fulcrum flexibility was 41.1%, traction flexibility 58.4%, and correction rate 59.6%. The median FBCI was 137% and TCI was 104.3%.Conclusions:When comparing fulcrum bend and traction radiographs, we found the traction radiographs to be more predictive of curve correction in AIS using pedicle screw constructs. TCI takes into account the curve flexibility better than FBCI.

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Nasal osteotomy is one of the most challenging steps of rhinoplasty. Lack of hands-on training and confidence with this procedure adds to the complexity for learners and trainees. As three-dimensional (3D) printing becomes increasingly accessible, simulation on 3D printed models has the potential to address this educational need in a safe, reproducible, and clinically realistic manner. The simulation session described in this communication, which utilized our low-cost, 3D-printed nasal osteotomy ($12.37) task trainer, produced both educational and confidence benefits for trainees. Here we describe the design, organization, curriculum, and pilot data for a 3D-printed nasal osteotomy task trainer for the simulation of endonasal and percutaneous nasal osteotomy.

Background For difficult or rare procedures, simulation offers an opportunity to provide education and training. In developing an adequate model to utilize in simulation, 3D printing has emerged as a useful technology to provide detailed, accessible, and high-fidelity models. Nasal osteotomy is an essential step in many rhinoplasty surgeries, yet it can be challenging to perform and difficult to receive adequate exposure to this nuanced portion of the procedure. As it currently stands, there are limited opportunities to practice nasal osteotomy due to the reliance on cadaveric bones, which are expensive, difficult to obtain, and require appropriate facilities and personnel. While previous designs have been developed, these models leave room for improvement in printing efficiency, cost, and material performance. This manuscript aims to describe the methodology for the design of an updated nasal osteotomy training model derived from anatomic data and optimized for printability, usability, and fidelity. Additionally, an analysis of multiple commercially available 3D printing materials and technologies was conducted to determine which offered superior equivalency to bone. Methods This model was updated from a first-generation model previously described to include a more usable base and form, reduce irrelevant structures, and optimize geometry for 3D printing, while maintaining the nasal bones with added stabilizers essential for function and fidelity. For the material comparison, this updated model was printed in five materials: Ultimaker Polylactic Acid, 3D Printlife ALGA, 3DXTECH SimuBone, FibreTuff, and FormLabs Durable V2. Facial plastic surgeons tested the models in a blinded, randomized fashion and completed surveys assessing tactile feedback, audio feedback, material limitation, and overall value. Results A model optimizing printability while maintaining quality in the area of interest was developed. In the material comparison, SimuBone emerged as the top choice amongst the evaluating physicians in an experience-based subjective comparison to human bone during a simulated osteotomy procedure using the updated model. Conclusion The updated midface model that was user-centered, low-cost, and printable was designed. In material testing, Simubone was rated above other materials to have a more realistic feel.

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